JPH0617080A - Urea grease composition - Google Patents

Abstract

PURPOSE:To obtain a urea grease which exhibits a desired consistency though it contains a small amt. of a thickener and which is excellent in mechanical stability, water resistance, pumpability, and acoustic characteristics. CONSTITUTION:A diurea compd. of the formula: R<1>NHCONHR<2>NHCONHR<3> (wherein R<2> is a tolylene group; and R<1> and R<3> are each a 16-18C linear or branched satd. or unsatd. hydrocarbon group) is mixed with a diurea compd. of the formula: R<4>NHCONHR<5>NHCONHR<6> (wherein R<5> is a diphenylmethane group; and R<4> and R<6> are each an 8C linear or branched satd. hydrocarbon group) in a molar ratio of the latter compd. to the former of 0.2-0.9, giving a thickener. A urea grease compsn. is prepd. by mixing a mineral oil and/or a synthetic oil as the base oil with the thickener in an amt. of 2-20wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a urea grease composition containing two kinds of diurea compounds as a thickener.

[0002]

2. Description of the Related Art Recently, in various industries such as automobiles and steel,
The progress of mechanical technology is remarkable, the miniaturization, weight reduction and performance improvement of various mechanical parts are progressing, and the lubrication point tends to become high temperature. Therefore, urea-based grease, which has excellent heat resistance and oxidation stability, is effective in reducing the amount used and extending the machine life, and is gradually expanding its applications. JP-A 1-2
The technology of No. 84591 discloses a diurea compound as a thickener, and this diurea compound has an alkyl group having 3 to 4 carbon atoms on one side of a divalent diphenylmethane group and 16 to 16 carbon atoms on the other side. It has 18 alkyl groups. The technique of JP-A-1-268793 also uses a diurea compound as a thickener, and this diurea compound is selected from the group consisting of an octadecyl group, an octyl group and a dodecyl group at both ends of a divalent diphenylmethane group. The groups are bonded and the octadecyl group has a molar ratio of 20 to 80 mol%. JP-A-1-139696 relates to a technique in which a diurea compound having a urea bond at both ends of diphenylmethane as a thickener and a diurea compound having a urea bond at both ends of a tolylene group or a vitylene group are used in combination. However, the alkyl bonded to the diphenylmethane group through the urea bond is limited to those having 8 carbon atoms, and the group bonded to the tolylene or vitrylene group through the urea bond is an aromatic group. It was limited. JP-A-2-77494 discloses a diurea compound of a type having a urea bond at both ends of diphenylmethane as a thickener,
The present invention relates to a technique of jointly using a diurea compound of a type having a urea bond at both ends of a vitrilene group. Tokusho Sho 6
The technology of 3-26798 uses three kinds of diurea compounds in combination, but the same group is used for both groups sandwiched between two urea bonds, and one compound has groups at both ends. Dodecyl, one compound having one end having dodecyl and the other end having octyl, and the other compound having both ends having octyl are used in combination. The technique of JP-A-58-185693 improves the acoustic characteristics by adding alkenyl succinic acid amide, metal salt of alkylbenzene sulfonic acid, metal salt of petroleum sulfonic acid, etc. to diurea type grease, but especially for diurea. There is no feature.

[0003]

[Object] A first object of the present invention is to provide a urea grease which can obtain a desired consistency with a small amount of a thickener and which is excellent in mechanical stability, water resistance, pumpability and acoustic characteristics. is there. A second object of the present invention is JP-A 1-1396.
The point is to extend and improve the technology of No. 96.

[0004]

The present invention includes the general formula (a) R ¹ NHCONHR ² NHCONHR ³ (wherein R ² is a tolylene group, and R ¹ and R ³ have 16 to ¹ carbon atoms).
8 is a linear or branched saturated or unsaturated alkyl group of 8) and (b) R ⁴ NHCONHR ⁵ NHCONHR ⁶ (wherein R ⁵ is a diphenylmethane group, and R ⁴ and R ⁶ are A mixture of diurea compounds represented by C8 straight-chain or branched saturated alkyl groups), wherein the proportion of (b) to (a) is 20 to 90 mol%, And / or 2 for the base oil consisting of synthetic oil
The present invention relates to a urea-based grease composition characterized by being contained in an amount of up to 20% by weight.

Component (a) is tolylene diisocyanate and hexadecylamine, heptadecylamine, and /
Alternatively, it can be obtained by reacting with octadecylamine. As tolylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, a mixture thereof or the like can be used. The component (b) is obtained by reacting diphenylmethane diisocyanate with octylamine.

[0006]

EXAMPLES The present invention will be described below with reference to examples. In addition, the characteristics of the urea grease of the present invention were clarified by also describing comparative examples. Examples 1 to 7 The diisocyanate of component (a) and 60 parts by weight of base oil were placed in a grease kettle at the compounding ratios shown in the table and heated to about 80 ° C. to dissolve the diisocyanate, and then 20 parts by weight thereof. The component (a), n-octadecylamine, dissolved in the base oil of 1) is gradually added and stirred vigorously. After about 10 minutes, diphenylmethane 4,4'-diisocyanate of component (b) was added, and then 20 parts by weight of n-octylamine dissolved in base oil was added and stirring was continued. The temperature rises due to the reaction between the diisocyanate and the amine, but after stirring for about 30 minutes in this state, the reaction is completed by heating to 170 ° C.
Then, it was left to cool to room temperature and kneaded to prepare grease.
The viscosity of the mineral oil shown in the examples is 11 cst (100 ° C), and the poly α-olefin oil is 12 cst (100 ° C). The consistency of the grease of each example, the dropping point, the shell roll (150 ° C., 24 h), the consistency after heating at 180 ° C. (25 ° C., immiscible), and the result of the acoustic test are shown in the table. The acoustic test was measured by the method described in JP-B No. 53-2357. Comparative Examples 1 and 2 Diisocyanate and 80 parts by weight of mineral oil were put in a grease kettle at a blending ratio shown in the table, heated to about 80 ° C. to dissolve the diisocyanate, and then 20 parts by weight of amine dissolved in mineral oil. Added and stirred. After continuing stirring in this state for about 30 minutes, the reaction was completed by heating to about 170 ° C., allowed to cool to room temperature, and then kneaded to prepare a grease. The properties of each comparative example are shown in the table. (Below margin)

[0007]

[Table 1]

[0008]

[Table 2] * The ratio of 2.4 / 2.6 in the comparative example is 65% / 35%. Consistency: JIS 2220 Shell roll: conforming to ASTM D1831 Acoustic test: According to the method described in Japanese Examined Patent Publication No. 53-2357.

Example 8 and Comparative Examples 3 to 5 As Example 8, a grease prepared by adding an antioxidant, a rust preventive agent and an extreme pressure agent to Example 6 was prepared, and the results were compared with commercially available grease. Shown in the table. The grease of the present invention is superior to the commercially available grease in mechanical stability, water resistance, heat resistance and pumpability.

[Table 3] (Note) Comparative Example 3: Commercial urea-based grease Comparative Example 4: Commercial lithium soap grease Comparative Example 5: Calcium complex-based grease

Comparative Examples 6 to 10 The data of Examples 1 to 4 and 9 of JP-A-1-139696 are shown as Comparative Examples 6 to 10.

[Table 4] From this table, it will be apparent that the present invention has a comprehensively improved acoustic effect as compared with the invention of JP-A-1-139696. Further, according to the present invention, a hard grease can be obtained with a small amount of thickener. In other words,
It is clear that the consistency yield is excellent. As described above, the urea-based grease composition of the present invention can provide a grease having not only improved acoustic characteristics but also excellent consistency yield, and excellent water resistance and mechanical stability from normal temperature to high temperature. .

[0011]

[Effect] The present invention can enrich the technology by presenting a new thickener formulation, and further improve the acoustic characteristics, which is the main problem of the prior art JP-A-1-139696. It was Moreover, the grease of the present invention has excellent mechanical stability at high temperatures and very little thermosetting property.

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Claims (1)

[Claims] 1. A compound represented by the general formula (a) R ¹ NHCONHR ² NHCONHR ³ (wherein R ² is a tolylene group and R ¹ and R ³ have 16 to ¹ carbon atoms).
8 is a linear or branched saturated or unsaturated alkyl group of 8) and (b) R ⁴ NHCONHR ⁵ NHCONHR ⁶ (wherein R ⁵ is a diphenylmethane group, and R ⁴ and R ⁶ are A mixture of diurea compounds represented by C8 straight-chain or branched saturated alkyl groups), wherein the proportion of (b) to (a) is 20 to 90 mol%, And / or 2 for the base oil consisting of synthetic oil
The urea-based grease composition is characterized by containing 20 to 20% by weight.